using System;
using System.Diagnostics;
using System.IO;

namespace Org.BouncyCastle.Utilities.IO
{
    public class TeeInputStream
        : BaseInputStream
    {
        private readonly Stream input, tee;

        public TeeInputStream(Stream input, Stream tee)
        {
            Debug.Assert(input.CanRead);
            Debug.Assert(tee.CanWrite);

            this.input = input;
            this.tee = tee;
        }

        protected override void Dispose(bool isDisposing)
        {
            try
            {
                input.Dispose();
                tee.Dispose();
            }
            finally
            {
                base.Dispose(isDisposing);
            }
        }

        public override int Read(byte[] buf, int off, int len)
        {
            int i = input.Read(buf, off, len);

            if (i > 0)
            {
                tee.Write(buf, off, i);
            }

            return i;
        }

        public override int ReadByte()
        {
            int i = input.ReadByte();

            if (i >= 0)
            {
                tee.WriteByte((byte)i);
            }

            return i;
        }
    }
}
